The present invention relates to a sheet feeding device adapted for use with printers or copying machines of various types, and serving to deliver paper sheets one by one to a predetermined position, and more specifically, to a sheet feeding device capable of feeding relatively small, thick cut sheets, such as postal cards and other cards, as well as thin ordinary paper sheets.
Conventionally, sheet feeding devices, used with various printers and copying machines, are adapted to feed thin cut sheets, such as printing sheets and copying sheets for general use. In these conventional feeding devices, separating claws are attached to a paper holder, as means for supporting thin cut sheets in a pile. The separating claws are located corresponding to two corner portions of each cut sheet on the leading end side thereof, with respect to a sheet feeding direction. When feed rollers rotate to deliver the thin cut sheets, the claws positively bend the corner portions of the leading end of each sheet, thereby separating the uppermost one of the sheets from the remainder. Thus, the thin cut sheets can securely be fed one by one.
The paper holder of the prior art sheet feeding devices of this type can be used only for thin paper sheets. Practically, therefore, it is difficult for those feeding devices to feed relatively rigid, thick cut sheets, such as postal cards, for printing or copying operation. More specifically, if the paper holder of one such conventional feeding device is used to feed thick cut sheets, the corner portions of the leading end of each sheet can hardly be bent by the separating claws. After all, the devices cannot feed thick cut sheets with ease.
A feeding mechanism has recently been proposed which is used exclusively for the feed of thick cut sheets. This mechanism cannot, however, be used without replacing a thin paper feeding mechanism. Such an arrangement entails high manufacturing cost, and requires troublesome work for the replacement.